Brake-shoe.



F. T. DICKINSON.

BRAKE SHOE. APPLICATION FILED OCT-18,1907- RENEVIED APR. 171 1916- 1 205,439. Patented Nov. 21, 1916.

2 SSSSSSSSS [ET' I F- T- DICKINSON.

Patented Nov. 21, 1916.

2 SHEETS-SHEET 2.

WIN

Hil

UNITED STATES PATENT OFFICE.

FRANK 'r. IJICKINsON, OF CHICAGO, ILLINOIS.

BRAKE-SHOE.

' Specification of Letters Patent.

Patented Nov. 21,1916.

Application filed October 18, 1907, Serial No. 397,994. Renewed April 17, 1916. Serial No. 91,747.

To all whom it may concern v Be it known that I, FRANK T. DICKI SON, a citizen of the United States, residing at Chicago, in the countyof Cook and State of Illinois, have invented certain new and useful Improvements in Brake-Shoes, of which the following is a specification.

My invention relates to. friction blocks for brakes employed on'railway cars, engines, etc., and particularly to that class of brake shoes which are formed by introducing into the body of the shoe reinforcing means and also means for improving the qualityof the wearing face of the same.

It has for itsobjects to provide a simple and efiicient reinforcement of'the shoe by means of strips of steel on the back of the shoe, to provide an efficient means of attaching the said reinforcing strips securely to the body portion of the shoe, to provide means for securely locking the elements of the shoe together, to provide a metal insert which is irregularly distributed throughout the body of the shoe thereby establishing areas in the wearing face of the shoe which are alternately of high and low friction qualities, to provide ametal insert of this nature which will not produce a scoring of the tread of the wheel with which it contacts, to provide such an insert which will notbecome separatedfrom the body of the shoe until the same is completely worn out, to provide a shoe of this class in which the portion of the wearing surface which is Occupied 'by the insertor inserts remain practically uniform but in which the insert Or inserts appear in the face of the shoe in a constantly shifting position. These and other objects which will hereinafter appear are obtained in my invention by a construction illustrated in preferred form in the accompanying drawings, wherein Figure 1 is a top plan view of a brake shoe showing the steel back, Fig. 2 is a longitudinal section of a shoe showing the steel back and the insert, Fig. 3 is a cross section on the line III-III Fig. 2, Fig. 4 is a plan view of the insert, Fig. 5 is a side elevation of an insert, Fig. 6 is anend view of an insert, Fig. 7 shows the steel strips inserted in the back of the shoe, Fig. 8 is a modified form of the strips shown in Fig. 7, Fig. 9 is a side elevation of the strip Fig. 8, Fig. 10 is another view of the insert employed.

Referring to Fig. 1, 1 is the body portion of the shoe, 2 is the attaching lug and 3 isithe slot for attachment to the brake'head. 4 are two pieces or strips of steel-on the back partially embedded in the body of-the' shoe and running throughout approximately the entire length of the shoe. '5 are holes in the ends ofthese steel back portions for receiving metal when the body of the shoe is cast and thereby attaching the steel. back to the body portion of the shoe. These steel back portions pass through the attaching lug which is provided for that purpose with oblique apertures 6 as shown in Fig. 3. By inclining the Opening 6 in the attaching lug from a horizontal the steelback portions are tilted on their outer edge thereby enabling the metal to flow up Over the outer edges of the same when the body portion of the shoe is cast thus partially submerging the steel back portions leaving the inner edges thereof exposed, the steel strips taking the position as illustrated in Fig. 1. The outer edge of the steel strips may be beveled which will give a further means of securing the same to the body-portion of the shoe when cast. It'will be Observed that strips 4 extend beyond the end lug 7 of the shoe, as most clearly shown in Fig. 2 giving strength to the shoe at point12. Thememher 4 in addition to the holes 8 is further provided with apertures 9 as shownin-F-ig. 7 which openings are completely-filled with metal, they being in the portion of the strips 4 which are on the inside of the attaching lug 2 and consequently are completely submerged by metal whenthe body portion of the shoe is cast, the metal being permitted to flow inside the lug 2 approximately to the opening 3 which is provided for attachment to the brake head. The strip t may be further provided near one or both of its ends intermediate the end of the shoe and the attaching lug with depressions -10 as shown in Figs. 8 and 9 which will enable the metal to completely submerge that portion of the steel strips when the shoe is cast. This -will provide an additional security against the severing of these strips.

Fig. 2 is a longitudinal section of'a brake shoe showing the position of the outeredge of the strip a, and of the insert 11.

Fig. 3 is a cross section showing the position of the strips and inserts 4: and 11. The general outline of the insert 11 conforms to the wearing face of the shoe as shown in Figs. 2 and 5.

In Figs. a and 5 the inserts 11 are shown in detail. Fig. 5 being a side elevation of the insert as it appears in the shoe and Fig. a being a plan view of the inserts as they appear when looking in the direction indicated by the arrow 13 in Fig. 2. It will be observed that by reference to Figs. 3 and 6 showing an end view of the inserts 11 that in shape it resembles an oblique frustum of a pyramid with the base toward the side and the apex extending toward the middle of the shoe, the two inserts approaching each other, closest at the points 1%, th intervening portions being separated and permitting metal to fiow between them when the body is cast. The inserts are arranged lengthwise preferably in eight sections a, b, c, d, e, f, g, h, and a, Z), 0, (Z, c, 7, g, h as indicated in Fig. a, and these sections traverse the shoe obliquely which gives to the inserts a staggered appearance as indicated; The successive sections of the inserts a and a, b and b, c and 0, (Z and (Z, c and e, f and f, g and g, h and h extend through the body of the shoe parallel to each other, arranged side by side and spaced ashort distance apart as above described. The sections of each insertare arranged in pairs a and b, c and (Z, 6 and 7", g and h, with similar pairs in the corresponding insert, the sections of each pair having their apices extending in the same direction, with the apices of the successive pairs extending in opposite directions. Referring to Fig. 4 traversing the length of the shoe from left to right it will be observed in the region of the shoe to the line AB, the apices of two sections of one of the inserts will appear in the face of the shoe whereas the bases of the corresponding sections of the other will appear in the face of the shoe, in the region from AB to (3-D there will be a reversal of this order since the apices of the successive pairs of sections of the inserts extend in opposite directions as above described, in the region from CD to E-F is another reversal the same order appearing as in AB to CD. It will thus appear as the shoe is worn away and the base of one section of an insert is gradually wearing away the apex of the corresponding section of the other insert is being worn down, so that as the width of one insert is being reduced parallel to the same section is a portion of the other insert which is gradually becoming larger. Thus the proportion of insert and main portion of the shoe which contacts with the wheel when the brakes are applied remains uniform whereas the region of the face of the shoe in which the portions of the inserts appear is constantly shifting. By producing a staggered insert such as I employ in my invention I not only obtain a shifting for th portions of the inserts in the face of the shoe but I obtain such a distribution of those portions as will distribute the wear of a particular point, and consequently a uniform wearing quality, in the inserts throughout diiferent portions of the wheel asthe shoe worn down, for it will be obvious, referring to Fig. t, that the angles made by the successive sections of the inserts occur in a b roken line on the face of the shoe and by the relative position of the two inserts in the shoe the angles formed by the parts of the inserts separately follow each other across the face of the wheel when the brakes are applied. The invention thus provides a complete and constantshifting of the high and low wearing regions on the face of the shoe as the same is worn. The insert may be of chilled metal with the body portion of softer material, or the insert may be of soft iron with a hard body portion as preferred.

Having thus described my invention and illustrated its use what I claim as new and desire to secure by Letters Patent is the following 1- 1. A brake shoe comprising in combina-f tion, a soft metal body portion provided with an attaching lug, and a hard metal insert having separated staggered Wearing faces of a cross section varying relatively to the radius of the shoe but presenting substantially the same amount of wearing surface disposed in the body portion adjacent the wearing surface thereof.

2. A b ake shoe comprising a body portion having an attaching lug, and a plu rality of oppositely disposed staggered wearing inserts embedded in the body portion adjacent the wearing surface thereof. V

3. A brake shoe comprising a body portion having an attaching lug, and a Pill. rality of oppositely disposed staggered wearing inserts embedded in the body portion adjacent the wearing surface thereof, staggered portions of the relatively soft metal of the body portion extending between said wearing inserts.

4. A brake shoe comprising a body portion having an attaching lug, and a plurality of oppositely disposed staggered wearing inserts embedded in the body portion adjacentthe wearing surface thereof, said wearing inserts being of different cross section. 7

5. A brake shoe comprising a body portion having an attaching lug, and a plurality of oppositely disposed wearing inserts embedded in the body portion adjacent the wearing surface thereof, said wearing inserts having certain portions wider than others thereof and extensions of the cast metal of the body of the shoe therebetween.

6. A brake shoe comprising in combination, a body portion provided with an attaching lug, and a wearing insert of a cross section varying relatively to the radius of the shoe but presenting substantially the 7 same amount of'wearing surface and having symmetrically-staggered portions embedded in the body portion adjacent the wearing surface thereof.

7. A brake shoe comprising a body portion, and an attaching lug secured to the said body portion, the body being provided in its wearing face with a metal insert extending throughout its length the said insert being composed of separated sections extending crosswise in the face of the shoe, substantially as described.

8. A brake shoe comprising a body portion, provided in its' wearing face with a metal insert extending longitudinally throughout the length of the shoe, the said insert being composed of a series of prisms with the base toward one side of the shoe and the apex toward the opposite side of the shoe, substantially as described.

9. A brake shoe comprising a body portion provided in its wearing face with a metal insert extending longitudinally throughout the length of the shoe, the said insert being composed of a series of pairs of oblique triangular prisms extending obliquely to the axis of the face of the shoe with their corresponding bases toward the side of the shoe and their apices toward the middle ofthe shoe, the successive pairs having apices and bases alternately appearing in the face of the shoe, substantially as described.

Gopies of this patent may be obtained for five cents each, by addressing the 10. A brake shoe comprising in combination, a body portion provided with an attachin lug, and a staggered wearing insert embed ed in the body portion adjacent the wearing surface thereof, said insert being of increasing cross section through a portion of its length and of decreasing cross section through another portion of its length.

11. A brake shoe comprising in combination, a body portion provided with an attaching lug, a plurality of wearing inserts having staggered portions embedded in the body portion adjacent the wearing surface thereof, and staggered portions of relatively soft metal between said staggered wearing portions.

12. A brake shoe comprising in combination, a body portion provided with an attaching lug, wearing inserts having staggered portions embedded in the body portion adjacent the wearing surface thereof, and staggered portions of relatively soft metal between said staggered wearing portions, said inserts being of increasing cross section through a portion of their lengths and of decreasing cross section through other portions of their lengths.

In testimony whereof I have hereunto signed my name in the presence of the two subscribing witnesses.

FRANK T. DICKINSON.

Witnesses PAUL CARPENTER, G. W. CUNNINGHAM.

Commissioner of Patents,

Washington, D. C. 

